In large marine vehicles, two distinct power requirements exist. One requirement is propulsion (i.e. power to drive the propeller shaft), the other is shipboard electrical service (i.e. lighting, computers, electronics, etc.). Since the power demands for propulsion and shipboard service are so different, separate and distinct power generation systems are generally provided. A typical mechanical propulsion plant would include two propulsion turbines, a reduction gear, two turbine generator sets, and two motor generator sets to supply propulsion and ship service electric power. Due to the large number of rotating machines, these existing systems tend to be noisy, large, heavy, and expensive to build and maintain. Existing electric propulsion systems for ships also tend to be very large and heavy due, in part, to the fact that separate electrical power generation must be provided for propulsion and shipboard service. As an alternative to separate power generators, there has been some suggestion of utilizing the same electrical generators for both propulsion and ship service. U.S. Pat. No. 4,661,714 discloses one such alternative in which the three-phase electrical power which drives the ship's propulsion motors also supplies the main shipboard electrical service through a transformer. A major disadvantage of such system is that propulsion motor voltage transients affect shipboard service, which typically includes electronic equipment that may be damaged or at least disrupted by major power fluctuations.